If global warming continues unchecked it will likely cause thousands of species to radically change in order to adapt to the changing planet — and we’re beginning to see some of those changes already. In southeast Alaska, near Juneau, researchers from the University of Alaska have found that in response to warmer waters resulting from climate change pink salmon are migrating upstream earlier than they did previously. This is the first time scientists have found evidence of genetic changes in pink salmon, and it could have broader implications for how animals adapt to the changing planet.

In a study published in the journal Proceedings of the Royal Society B, Alaskan researchers observed populations of pink salmon in Auke Creek. In the 1980s, one of the researchers that participated in the current study, UAF Fisheries and Ocean Sciences professor Anthony Gharrett, intentionally bred a genetic marker into some of the pink salmon — a marker that would neither help nor hurt the fish, but that could be used to monitor them. Since then, Genetic samples of the fish have been taken regularly, enabling the team to observe that the genetic marker decreased over time from 20 percent of the population to 10 percent — showing genetic change.

In the 1980s, the presence of the genetic marker in pink salmon populations at Auke Creek was fairly stable, University of Southeast’s David Tallmon told the Alaska Dispatch, but a rapid decline began showing up in 1989 — the same year that the second-highest water temperatures were recorded. The research also shows that the window of migration is narrowing for pink salmon; previously they would migrate over a 60-day period, but now it’s limited to 40 or 45 days. Asked if slower evolutionary changes in other salmon species could account, at least in part, for declining populations, Tallmon said it’s “definitely a possibility.”